In order to clarify the multidimensional spatial distribution characteristics and the water-salt coupling relationship of soil salinity, the Shandong part of the Bohai Rim Plain was taken as the research area. Data were obtained through field measurements and indoor analyses, and descriptive statistical analysis of soil water-salt characteristics were carried out based on classical statistical methods. GIS software was used to analyze the two-dimensional spatial distribution of soil salinity and water content, and GMS software visualization was used to and analyze the three-dimensional spatial differentiation characteristics of soil salinity. A soil water-salt coupling coordination model was constructed to quantitatively analyze the degree of influence of different factors on water-salt coupling coordination. The results showed that: (1) The median soil salinity in the study area was 2.08 g/kg, with moderately saline soils dominating, and the overall soil salinity showed a gradual increase from top to bottom; the mean value of surface soil water content was 15.38%, and the whole region was relatively water-scarce. (2) In the two-dimensions, the area with soil water content less than 20% was 17 519.48 km², which accounted for a total of 86.64%; the soil salinity in the surface layer (0—20 cm) was dominated by mildly saline soils, with an area of 10 051.87 km², accounting for 49.71% of the total area. Soil water content and soil salinity both showed an increasing trend from south to north. (3) The water-salt coupling degree in the area north of Dongying District was mostly greater than 0.66, while the coupling degree in the area south (except Pingdu and Laizhou City) was mostly concentrated in the range of 0.40-0.66, forming a spatial pattern in which the intensity of water-salt interaction in the area north of Dongying District as a whole was greater than that in the area south. (4) The southern part of the study area was dominated by low coordination and medium coordination, while the northern part was dominated by higher coordination and high coordination. elevation, average temperature, average rainfall and NDVI had the strongest influence on the coordination of water-salt coupling, with correlation coefficients of 0.26, 0.25, 0.25 and 0.21 respectively. The results of the study can provide a theoretical basis for the rational development and utilization of saline soil resources in the Bohai Sea Plain region.